In experiments to study the properties of subatomic particles, physicists routinely accelerate electrons to speeds close to the speed of light. An electron has a mass of $9\mathrm{.}11$ x $10^-$³¹ kg and moves with a speed of $0\mathrm{.}99$c$.$

 a$.$ Calculate the electron's momentum using the non$-$relativistic equation.

b$.$ Calculate the electron's relativistic momentum. Compare the relativistic momentum and the non$-$relativistic momentum.